Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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FXUS66 KSEW 121731
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
925 AM PST Mon Nov 12 2018

.SYNOPSIS...An upper ridge will keep the area dry through Tuesday. A
front will bring light rain to the Washington coast by Tuesday
afternoon, spreading inland Tuesday night and Wednesday. Another dry
period with areas of night and morning fog is expected Thursday
through Saturday. A front may bring some light rain to the area by
late Sunday or early next week.

&&

.SHORT TERM...A quick look at current conditions shows that fog has
cleared out faster than anticipated in current forecast...nothing a
few quick edits and a forecast update cannot handle. Speaking of
current conditions...obs from the Wind Advisory area show that winds
are easing there a bit. Will continue to monitor...but if current
trend holds the noon expiration there looks to be fine. Models
continue to suggest fairly decent gradients in that area throughout
the day...although the NAM is proving a bit stronger than the
GFS...so there is certainly a case that it may need to be extended
as well. As already stated...will continue to monitor and act
accordingly.

Covered the now so thoroughly mainly because there is not much in
the way of activity expected over the next 24 hours...as high
pressure continues its slow eastward progression over the area
today. This will result in fair skies over the area and as
such...not a whole lot worth writing about.

Next system progged to enter the area Tuesday evening with models in
general agreement on timing and precip amounts/coverage. This system
will linger into Wednesday before tapering off Wed evening. Falling
to typical model characteristics...the GFS is quicker to move things
along with activity tapering off Wed evening while the ECMWF hangs
on to things a bit longer into the overnight hours and very early
Thursday morning. Inherited forecast looks to be a split of these
two solutions and currently see no argument to deviate from such
thinking at this time.  SMR

.LONG TERM...From Previous Discussion...High pressure aloft begins
to build offshore Thursday. This will lift the baroclinic band
northward mostly across southern British Columbia. Weak systems
moving along this storm track will brush northern Washington
Thursday with some light rain possible. Areas around Puget Sound
should stay dry.

The GFS/ECWMF amplify the ridge just offshore, then shifts it over
the region over the weekend. Some past model solutions were
bringing in some wet systems toward the end of the week and the
weekend. However, most global models now show dry weather through
the weekend. Kept some low pops in the forecast Sunday as
confidence in timing of the next system is low. Early next week
may bring wetter conditions. Mercer

&&

.AVIATION...The air mass across Western WA will remain dry and
stable today with high pressure aloft and offshore flow. VFR
conditions expected. SCT-BKN cirrus clouds aloft. Rain will increase
Tuesday night as the next frontal system approaches and moves
inland. 33

KSEA...Dry weather today with VFR conditions. E/NE winds to 10 kt.
33

&&

.MARINE...Offshore flow will persist through Tuesday with high
pressure east of the Cascades and low pressure over the NE Pacific.
Highest wind and waves will be over the Coastal Waters and western
Strait of Juan de Fuca - Small Craft Advisories are in effect. The
flow will turn onshore late Tuesday into Wednesday as a weak front
crosses the area. A second weak frontal system will clip the region
on Thursday. Offshore flow will return over the weekend. 33

&&

.HYDROLOGY...River flooding is not expected the next 7 days.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory until noon PST today for East Puget Sound
Lowlands.

PZ...Small Craft Advisory until 4 AM PST Wednesday for Coastal Waters
     From Cape Flattery To James Island 10 To 60 Nm-Coastal
     Waters From Cape Flattery To James Island Out 10 Nm-Coastal
     Waters From James Island To Point Grenville 10 To 60 Nm-
     Coastal Waters From James Island To Point Grenville Out 10
     Nm-Coastal Waters From Point Grenville To Cape Shoalwater
     10 To 60 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater Out 10 Nm.

     Small Craft Advisory until 10 PM PST Tuesday for West Entrance
     U.S. Waters Strait Of Juan De Fuca.

&&

$$

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